Associate QA Engineer

A foundations course that builds eleven core data structures from the ground up (arrays, matrices, stacks, queues, linked lists, trees and BSTs, hash tables, hash sets, heaps, graphs and tries), then covers sorting, searching, greedy and divide and conquer. Every chapter has practice problems, flashcards and an assessment. It suits students and career switchers whose foundations came from tutorials and who find pattern courses move too fast.

• Job search
• DSA
• CS fundamentals

A browsable practice library of coding problems that can be filtered by pattern, data structure, difficulty and company, so you can drill exactly the weakness you found this week. Patterns include two pointers, sliding window, hash maps, stacks, backtracking and greedy algorithms, with company filters for Google, Meta, Microsoft, Amazon, Oracle and LinkedIn. Free to browse, with an in-browser editor and solutions.

• Job search
• DSA

A free newsletter of short, focused posts on system design and problem solving, from the team behind the Grokking courses. Recent posts cover company interview processes (such as OpenAI and Anthropic roles), the most asked mobile system design questions and preparation plans, each linking to a fuller article on the blog. It suits engineers who want a steady, low-effort way to keep system design and interview topics fresh between deeper study sessions.

• System design
• DSA

The official Android developer guides and reference: Jetpack Compose UI, data and files, permissions, navigation, background work with WorkManager, camera, location, connectivity, testing, performance tools and releasing your app, plus guides for phones, tablets, foldables, Wear OS, TV, cars and XR. It suits developers who have finished a beginner course such as Android Basics with Compose and need accurate, current answers while building real apps.

• Mobile
• Testing

Apple's official reference and guides for building apps on its platforms: Swift, SwiftUI, UIKit, SwiftData, Foundation, networking, notifications, location, testing, Instruments and app distribution. Tutorials get you started, but this is where iOS and macOS developers look things up once they are building their own app. Many framework pages include runnable sample code projects, and it is free to use without a paid developer account.

• Mobile
• Testing

An intentionally vulnerable web store from the OWASP Foundation that packs the entire OWASP Top Ten, plus other real world flaws, into one modern JavaScript application. It is a standard legal practice target for learning web application security and for trying out security testing tools, and it runs locally in minutes with Docker or npm.

• Web
• Testing
• Programming
• CS fundamentals